Extra bytes are added when I run my compressed file in my decompression method

Question

I'm working with text files here. My LZW decompression doesn't seem to work correctly. Something is wrong when I try to decompress my compressed file back: I get extra bytes added to the text file after decompression. As of now, I found the sequence of values that's causing the issue, it's the * (star character)

For example, When I have a text file containing this following sentence:

*** Hello ***

Here's how my decompression works (I'm showing only 2 iterations):

#1 iteration
priorword = 42
currword = 256
Added in dict: 256: ** 

Wrote in file: **

#2 iteration
priorword = 256
currword = 32
Added in dict: 257: **_     (_ means space)
Write in file: **


We know have in file: ****_

What could be wrong here, an extra star gets added because as you can see the original file has three stars.

After decompression, I get: **** Hello **

A star * from the right is added to the left, how could this be?

Decompression method:

public void LZW_Decompress(String input) throws IOException {
        // DictSize builds up to 4k, Array_Char holds these values
        Array_char = new String[4096];

        for (int i = 0; i < 256; i++) {
            dictionary.put(i, Character.toString((char) i));
            Array_char[i] = Character.toString((char) i);
        }

        // Read input as uncompressed file & Write out compressed file
        RandomAccessFile in = new RandomAccessFile(input, "r");
        RandomAccessFile out = new RandomAccessFile(input.replace(
                ".lzw", ""), "rw");

        try {
            // Gets the first word in code and outputs its corresponding char
            buffer[0] = in.readByte();
            buffer[1] = in.readByte();
            priorword = getvalue(buffer[0], buffer[1], onleft);
            onleft = !onleft;
            out.writeBytes(Array_char[priorword]);

            // Reads every 3 bytes and generates corresponding characters
            while (true) {
                if (onleft) {
                    buffer[0] = in.readByte();
                    buffer[1] = in.readByte();
                    currword = getvalue(buffer[0], buffer[1], onleft);
                } else {
                    buffer[2] = in.readByte();
                    currword = getvalue(buffer[1], buffer[2], onleft);
                }
                onleft = !onleft;

                if (currword >= dictSize) {
                    if (dictSize < 4096) {
                        Array_char[dictSize] = Array_char[priorword]
                                + Array_char[priorword].charAt(0);
                    }
                    dictSize++;
                    out.writeBytes(Array_char[priorword]
                            + Array_char[priorword].charAt(0));
                } else {
                    if (dictSize < 4096) {
                        Array_char[dictSize] = Array_char[priorword]
                                + Array_char[currword].charAt(0);
                    }
                    dictSize++;
                    out.writeBytes(Array_char[currword]);
                }
                priorword = currword;
            }
        } catch (EOFException e) {
            in.close();
            out.close();
        }
    }